A transmission is a speed and power changing device for changing the ratio between an engine operating speed and driving wheel operating speed to best meet each particular driving situation. Each vehicle is equipped either with a manual, automatic or semi-automatic transmission.
Manual transmissions are equipped with a clutch which connects and disconnects a driving force from a driven member. A shift lever is used to manually change the power flow from different drive gears to different driven gears so as to vary an output operating speed. These transmissions have relatively simple and reliable mechanical design but require more driver skill which makes them unpopular in some markets. Another disadvantage of manual transmissions is clutch wear and tear which occurs over time and requires clutch replacement. Bicycles are equipped with manual transmissions which apply a drive chain for connecting driving and driven members and changing the ratio between pedalling speed and wheel operating speed.
Except for simple motorcycles (such as mopeds and motor-scooters), automatic transmissions are of relatively complicated design but require minimum driver skill and, consequently, are very popular in the U.S. market. Instead of a clutch, they apply a torque converter to connect and disconnect a driving force from a driven member.
Gear ratios in, both, manual and automatic transmissions have significantly different values and, thus, engine speed cannot be kept at optimum level at all times resulting in a related energy loss. Bicycle transmissions have an extensive range of ratios but during every shifting require a chain relocation from one gear to another which also results in power loss.
Therefore, it is an object of the present invention to provide such transmission which will be power efficient, simple to maintain, and comfortable to use.